As imaging techniques for obtaining a depth-direction distance as two-dimensional array information, various methods are being developed, such as a technique utilizing reference light and a stereo distance measurement technique utilizing more than one camera. Particularly, in recent years, there is an increasing demand for relatively inexpensive products as novel input devices for consumer use.
Therefore, an imaging device that has an imaging lens as a structure to obtain a large number of parallaxes with many lenses and restrain decreases in resolution has been suggested. This imaging device includes an imaging-type lens and optical systems serving as a re-imaging-type optical system placed between the imaging-type lens and the imaging element, for example. The optical systems may be formed by a microlens array having a large number of minute lenses formed on a flat face, for example. Pixels that capture images from the microlenses are provided at the corresponding locations under the respective microlenses. An image formed at the imaging lens is again formed on the imaging element by re-imaging microlenses. The re-imaged single-lens image is an image with a viewpoint deviation that is equivalent to the parallax existing at each location of the microlenses. By performing image processing on parallax images obtained from a large number of microlenses, the distance to the subject can be estimated based on the principles of triangulation. Also, by performing image processing to combine images, a two-dimensional image can be reconstructed. As an example of the image processing technique for estimating the distance to the subject, a general-purpose stereo image processing technique can be used. By such a stereo image processing technique, images are compared, and the portions formed by imaging the same point on the subject are determined by an image matching technique or the like.
However, there is a problem that the optical color cross talk between adjacent microlenses lowers the accuracy of matching parallax images.